Multiple Choice
In the principles of transmembrane transport, what type of energy is typically required to drive primary active transport across a membrane against an electrochemical gradient?
21
views
9. Transport Across Membranes
Principles of Transmembrane Transport
Multiple Choice
Which of the following is an example of active transport across a cell membrane?
A
Transport of out of the cell and into the cell by the / ATPase
B
Facilitated diffusion of glucose through a GLUT transporter down its concentration gradient
C
Movement of across the lipid bilayer down its concentration gradient
D
Osmosis of water through aquaporins toward higher solute concentration
Verified step by step guidance1
Understand the definition of active transport: it is the movement of molecules across a cell membrane against their concentration gradient, requiring energy, usually in the form of ATP.
Identify the example involving movement against concentration gradients and energy use. The transport of Na\(\textsuperscript{+}\) out of the cell and K\(\textsuperscript{+}\) into the cell by the Na\(\textsuperscript{+}\)/K\(\textsuperscript{+}\) ATPase pump fits this description because it moves ions against their gradients using ATP.
Recognize that facilitated diffusion of glucose through a GLUT transporter is passive transport because it moves glucose down its concentration gradient without energy expenditure.
Note that the movement of O\(\textsubscript{2}\) across the lipid bilayer down its concentration gradient is simple diffusion, a passive process that does not require energy.
Understand that osmosis of water through aquaporins toward higher solute concentration is also passive transport driven by water potential differences, not requiring ATP.
Related Videos
Related Practice
